To Update Samsung Galaxy S2 GT-I9100 Software you need to install a newer firmware version on it. You can update your Samsung Galaxy S2 GT-I9100 without a computer by going to Settings > About Device > Software Update. Also, You can update this Samsung device manually, But you need to use a computer.
In this Guide, You will learn how to update Samsung Galaxy S2 GT-I9100 manually by using the Odin3 flasher and Samsung Stock Firmware files.
The explained steps in this Guide will help you to Factory Reset Samsung Galaxy S2 with model numbers:Samsung GT-I9100. Samsung GT-I9100G. Samsung GT-I9100L. Samsung GT-I9100M. Samsung GT-I9100P. Samsung GT-I9100T. Samsung Galaxy S2 GT-I9100 Factory Reset Checklist:
1- This process restores the Android platform to its original state and wipe all your data, So backup all the wanted data (Contacts, SMS, Photos, Videos,… Etc).